Method of forming a machinery support



Jan. 3, 1967 w. .1. BURcH METHOD OF FORMING A MACHINERY SUPPORT Original Filed Dec. 5 1963 ATZY.

United States Patent() METHOD F FORMING A MACHINERY SUPPORT William J. Burch, Annapolis, Md., assigner to the United States of America as represented by the Secretary of the Navy Original application'Dec. 5, 1963, Ser. No.'328,437.

The-inventiondescribed herein-may be manufactured and used by ory for the Government of the United States of America for governmental purposes without the payment of any royalties thereon and therefor.

This application is a divisional application of applicants copending application Serial No. 328,437, `filed December 5, 1963, entitled `Machinery Foundation and Method of Assembling.

The `present invention relates to machinery supports and more particularly, to vibration and shock, damping and isolating supports. While the machinery support of the present invention will be described as employed aboard a ship or submarine, it should be understood that it could be effectively employed wherever it is desired to dampen machine vi-brations and isolate them from their surrounding environment.

It is desirable to keep vibrations to a minimum on ships-and submarines because they are noisy and nnpleasant to the shipboard personnel and also, they are easily transmitted throughwater and can be picked up and used by others to determine the position of the ship.

`The latter phenomenon is particularly dangerous in war- In existing -machine foundation assemblies, one type of `structure is used to isolate the machine vibrations, and

a separate structure is employed to dampen machine vibrations. For example, resilient isolation mounts are placed between the machine and its support, and damping materials are applied externally to` the support components. The use of'separate structures has not proved entirely -satisfactory for several reasons. `One reason is that they are expensive. Also, they take up additional space, and

'incertain environments, e.g., on submarines, space is limited. Consequently, due to lack of space, one of these `stmctures must be eliminated, and the remaining struc- -ture is not entirely effective alone.

Moreover, the application of damping materials to machine supports often `requires that either the support Vstructure and/or the damping treatment be modified, sacrificing some of their effectiveness.

The general purpose of the present invention, therefore, is to provide a .machinery support which Will dampen and isolate machinery vibrations while protecting the machinery fromshock forces emanating from the foundation upon which the support stands via` a single structure and to provide an optimum method of assembling the support. lIn accordance with the present inventiomthis is accomplished, generally, by placing a body of damping and isolating material between the machine and the foundation.

`An object of this `invention is to provide an improved machine support which is easier and less expensive to manufacture.

ICC

Another object of this invention is to provide a machinery support which will, through the use-of one and the same structure, (l) isolate the machine vibrations, (2) dampen the machine vibrations, and (3) protect the machine Ifrom shock pulses from the foundation upon which the support stands.

Still another object of the present invention is to provide a mach-ine support which will occupy less space than existing machine foundations which perform the same functions.

A further object of the present invention is to provide an improved method of assembling a machine support which dampens and isolates machinery vibrations.

A still further object of the present invention is to provide a machine support structure Iwhich may have its components parts manufactured in a shop and may be quickly, easily, and effectively assembled at the location where the support will be employed.

Other objects and advantages of the invention will hereinafter become more fully apparent from the following description when read in conjunction with the annexed drawings, in which:

FIGURE l is a view ofV an overall embodiment of this invention illustrating its application as a machinery support;

- FIGURE 2 is a detailed sectional view of one of the supports of FIGURE l taken along the line 2--2 of PIG- URE 1; and

FIGURE 3 is a sectional view of an alternative embodiment of one of the supports of FIGURE l.

Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in FIGURE 1 a piece of machinery mounted on a foundation top 12 which is in turn mounted upon supports |14 of the present invention. As seen in 'FIGURE 2, support 14 includes an outer column component or base member 216 shown as a tubular shell, an inner column component 1'8 shown as a support member havinga depending projection, and a vibration damping substance' 20 interposed Vbetween the outer and inner column components to prevent metal-tometal contact therebetween.

Outer column component 16 is secured at its lower end to a floor or ship deck, as bywelding 24. There are vents 26 through the well of the outer column ycomponent for a purpose described hereinafter and plugs 28 Aclosing the vents. Positioning screws 30 also extend through the outer column component wall for centering the inner column component within the cavity 32 in the outer column component but spaced from the peripheral Wall 34'of the cavity. Although outer column component 16 is shown as having its bottom end open, cavity 32 could terminate .short of the bottom end of the outer column component leaving the-bottom end closed. Grease fittings 35 also extend through the outer column component for providing a passage for introducing the damping substances '20 into cavity 32, as will be more fully described hereinafter.

Inner column component or'support member 18 has foundation top 12 welded at 38 to its top end for supporting machinery thereon. The inner column component is hollow which renders it lightV and is closed at its bottom end by a cap plate 40 to prevent the Vibration damping substance 20 from filling `the hollow area. If greater damping is desired, the cap plate may be elimi- Inatcd and damping substance 20 permitted to fill the hollow area.

The vibration damping material 2t) is composed of a two-part, self-setting, room temperature curing, viscoelastic compound, such as Miracle `Adhesives Corporation Type CA-40 Flexible Epoxy-Lead Filled Resin which has a durometer hardness between 60 and 80 at 75 F. The compound may be introduced in a liquid state into cavity 32 through the use of a grease gun and grease fittings 35 and should then be allowed to set or polymerize whence it will bond or adhere to the metallic surfaces which it separates.

The Visco-elastic damping material, after it has set, will support inner column component 18 in cavity 32 and will dampen any vibrations imparted to the 4inner column component by the machinery. Also, its bond strength will enable it and support 14 to resist the extreme inertial forces associated with exposure to high impact shock conditions. Proper selection of the visco-elasticmaterial will depend on the temperature characteristics of the use environment. lating and damping material, it should not be temperature responsive to the extent that it could be classified as a thermoplastic; i.e., it should not repeatedly harden and soften when exposed to low (32 F.) and high (100 F.) temperatures. Material which is non-thermoplastic in this relatively restricted temperature range will ensure maximum effectiveness without dependence on environment temperature. In the event that environment temperatures are to be essentially or almost constant, a material that exhibits maximum effectiveness at that temperature may be profitably employed.

In assembling support 14, the welding of the outer column component to the floor or deck, and the welding of the foundation top to the inner column component'should be done out of the vicinity of the damping materials since the high temperatures generated by the welding operations might cause degradation of the effectiveness of the constrained damping material due to physical and/ or chemical property changes. Support 14 is assembled in the following manner: Outer column component 16 is welded to the floor or deck at its lower end, and foundation top 12 is welded or otherwise secured to the upper end of inner column component 18. Now the inner column component is inserted into cavity 32 and held suspended therein. The positioning screws 30 are now tightened to hold the inner column component in cavity 32. Next the damping material 20 in liquid form is injected into the cavity 32 through one of the grease fittings 35 by a grease gun. As damping material 20 fills the lower end of cavity 32 and moves up to fill the annular space between inner and outer columns components, it will ow out of the vents 26. This will assure the personnel who are assembling the support that there are no substantial air pockets in the cavity 32. When the damping material begins to tiow out of each vent, a plug 28 is inserted'in the vent to close it and stop the leakage. After the damping material fills the lower portion of cavity 32, one or more additional grease fittings may be employed to fill the upper portions. The filling of cavity 32 from the bottom up will help insure against air pockets in the cavity. When the level of the damping material reaches the top of outer column component 16, the filling operation is ceased, and the damping material is allowed to set or polymerize. As hereinabove set forth, as the liquid polymerizes it will bond to the surfaces of the inner and outer column components.

After the damping material 20 polymerizes, it will be able to support the inner column component in cavity 32.

Now, positioning screws 30 may be removed since the polymerized damping material will maintain and support the inner column component in the center of cavity 32.

For maximum effectiveness, both as an iso- Plugs may be inserted into the wall of the outer column component to fill the spaces left by the positioning screws 30. The very small spaces in the damping material left by the removal of the positioning screws are normally of no consequence. If desired, however, they may be filled with an elastic putty. As can be seen, a support is now assembled wherein there is no metal-to-metal contact between the machinery foundation top and the deck of the ship. Damping material 20 serves the dual function of damping the inner column component and isolating the 4 inner and outer column components, one from the other. The support 114 shown in FIGURE 3 is similar to the support i4 of FIGURE 2 and may be used in place thereof. The inner and outer column components 16 and 18 and damping material 20 are identical to inner and outer column components and damping material of support 14.

The bottom of the cavity 32, however, is filled with a plurality of air filled,v flexible hollow spheres 150. A porous sheet of material, such as a porous sintered metal fiber sheet 152 is placed on top of the spheres 150 for a purpose described below, and the spaces between spheres are filled by damping material 20. The inclusion of air filled, flexible hollow spheres, which should be rubber or elastomeric plastic, provides more effective isolation and a dissipative barrier between the high impact shock forces from the ships deck and the machinery supported.

To assemble support 114, outer column component 16 is welded to the deck and foundation top 12 is` cavity 32. Damping material 20 is now injected in liquid form into cavity 32 via lowermost grease fitting 35, and Ibeing so injected will flow into and flill the spaces between the `spheres 150, and will fiow through the porous sheet to fill the annular space between the inner and outer column component. Vents 26 and additional grease fittings may be employed in the same manner and for the same purpose described in the assembling process of support 14 above. The damping `material is now allowed to polymerize, after which it will be able to support inner column component 18 within cavity 32, and positioning screws 30 are removed. The air filled, flexible hollow spheres add to the effectiveness of the isolation of the machine vibrations.

The porous sheet of material 152 is used as a barrier to prevent the hollow spheres from floating up between the inner column component and the peripheral wall of ycavity 32 when the damping material is injected into cavity 32 in liquid form.

Various modifications are contemplated and may obviously be resorted to by those skilled in the `art without departing from the spirit and scope of the invention, as hereinafter defined by the appended claims, as only preferred embodiments thereof have |been disclosed.

What is claimed is:

1. A method of forming a support member for damp-1 ing and isolating the vibrations produced by machinery t adapted to be supported on a floor or the like, comprising the steps of securing a hollow firstcolumn member to said floor in a position substantially normal to said floor;

filling the bottom portion of said -hollow first column member a pre-selected depth into said hollow first column member; v temporarily securing said second column member within said hollow first column member at said pre-selected depth by means carried by said first` column member;

said means for temporarily securing said second column member within said hollow first column membr bfiflg Operable to space the opposing peripheries of said column members a pre-selected distance apart and to thereby separate said first and second column members;

introducing a self-setting, Visco-elastic material into said hollow rst column member at selected points along the length thereof to `set and occupy the space within said hollow first column member between the opposing peripheries of said first and second column members; and

removing the means carried by said hollow first column member for temporarily securing said second column member within said hollow first column member;

said Visco-elastic material when set being bonded to said rst and second column members and functioning to separate said first and second column members and to hold said first and second column members in assembly;

said set Visco-elastic material being operable to dampen the vibrations produced by said machinery, to isolate said vibrations from said floor and to isolate said machinery from high shock loads emanating from said floor.

2. A method of forming a support member for damping and isolating the vibrations produced by machinery adapted to be supported on the deck of a ship or the like, comprising the steps of securing a first column member having a vertically extending and upwardly opening cavity therein to said deck;

filling the bottom portion of said cavity in said first colu-mn member with a plurality of flexible spherical elements;

placing a porous sheet material element within said cavity on top of said fiexible spherical elements; securing a machinery support member to one end of a second column member; inserting the opposite end of said second column member a pre-selected depth into said cavity in said first column member;

temporarily securing said second column member within said cavity in said first column member at said pre-selected depth by means carried by said first column member;

said means for securing said second column member within said cavity in said first column member being operable to space the opposing peripheries of said column members a pre-selected distance apart and to thereby separate said first and second column members;

introducing a self-setting, Visco-elastic material into said cavity within said first column member at se lected points along the length of said first column member to set and occupy the space within said cavity between the opposing peripheries of said first and second column members; and

removing the means carried by said first column member for temporarily securing said second column member within said cavity in said first column member;

said Visco-elastic material when set being bonded to said first and second column members and functioning to both separate said first and second column members and to hold said first and second column members in assembly, said Visco-elastic material when set being operable to damp the vibrations produced lby said machinery, to isolate said vibrations from said floor, and to isolate said machinery from shock loads emanating from said floor.

References Cited by the Examiner UNITED STATES PATENTS 1,387,288 8/ 1921 Menefee 264-261 XR 2,845,657 8/ 1958 Beare 264--262 XR 3,016,578 1/ 1962 Rohe 264-262 FOREIGN PATENTS 835,240 3/ 1952 Germany.

ROBERT F. WHITE, Primary Examiner.

ALEXANDER H. BRODMERKEL, Examiner.

T. I. CARVIS, Assistant Examiner. 

2. A METHOD OF FORMING A SUPPORT MEMBER FOR DAMPING AND ISOLATING THE VIBRATIONS PRODUCED BY MACHINERY ADAPTED TO BE SUPPORTED ON THE DECK OF A SHIP OR THE LIKE, COMPRISING THE STEPS OF: SECURING A FIRST COLUMN MEMBER HAVING A VERTICALLY EXTENDING AND UPWARDLY OPENING CAVITY THEREIN TO SAID DECK; FILLING THE BOTTOM PORTION OF SAID CAVITY IN SAID FIRST COLUMN MEMBER WITH A PLURALITY OF FLEXIBLE SPHERICAL ELEMENTS; PLACING A POROUS SHEET MATERIAL ELEMENT WITHIN SAID CAVITY ON TOP OF SAID FLEXIBLE SPHERICAL ELEMENTS; SECURING A MACHINERY SUPPORT MEMBER TO ONE END OF A SECOND COLUMN MEMBER; INSERTING THE OPPOSITE END OF SAID SECOND COLUMN MEMBER A PRE-SELECTED DEPTH INTO SAID CAVITY IN SAID FIRST COLUMN MEMBER; TEMPORARILY SECURING SAID SECOND COLUMN MEMBER WITHIN SAID CAVITY IN SAID FIRST COLUMN MEMBER AT SAID PRE-SELECTED DEPTH BY MEANS CARRIED BY SAID FIRST COLUMN MEMBER; SAID MEANS FOR SECURING SAID SECOND COLUMN MEMBER WITHIN SAID CAVITY IN SAID FIRST COLUMN MEMBER BEING OPERABLE TO SPACE THE OPPOSING PERIPHERIES OF SAID COLUMN MEMBERS A PRE-SELECTED DISTANCE APART AND TO THEREBY SEPARATE SAID FIRST AND SECOND COLUMN MEMBERS; INTRODUCING A SELF-SETTING, VISCO-ELASTIC MATERIAL INTO SAID CAVITY WITHIN SAID FIRST COLUMN MEMBER AT SELECTED POINTS ALONG THE LENGTH OF SAID FIRST COLUMN MEMBER TO SET AND OCCUPY THE SPACE WITHIN SAID CAVITY BETWEEN THE OPPOSING PERIPHERIES OF SAID FIRST AND SECOND COLUMN MEMBERS; AND REMOVING THE MEANS CARRIED BY SAID FIRST COLUMN MEMBER FOR TEMPORARILY SECURING SAID SECOND COLULMN MEMBER WITHIN SAID CAVITY IN SAID FIRST COLUMN MEMBER; SAID VISCO-ELASTIC MATERIAL WHEN SET BEING BONDED TO SAID FIRST AND SECOND COLUMN MEMBERS AND FUNCTIONING TO BOTH SEPARATE SAID FIRST AND SECOND COLUMN MEMBERS AND TO HOLD SAID FIRST AND SECOND COLUMN MEMBERS IN ASSEMBLY SAID VISCO-ELASTIC MATERIAL WHEN SET BEING OPERABLE TO DAMP THE VIBRATIONS PRODUCED BY SAID MACHINERY, TO ISOLATE SAID VIBRATIONS FROM SAID FLOOR, AND TO ISOLATE SAID MACHINERY FROM SHOCK LOADS EMANATING FROM SAID FLOOR. 